JPH08-144811A, published by the Japan Patent Office in 1996, discloses a supercharging internal combustion engine comprising an air flow meter, a compressor of a turbocharger disposed on a downstream side of the air flow meter, a throttle disposed on a downstream side of the compressor, a bypass passage that bifurcates from an intake passage between the compressor and the throttle and converges with the intake passage between the air flow meter and the compressor, and a bypass valve that opens and closes the bypass passage. The bypass valve is controlled to circulate air on the downstream side of the compressor between the air flow meter and the compressor, thereby ensuring that a supercharging pressure does not increase excessively.
When the throttle of the internal combustion engine is fully closed during vehicle deceleration, the air flow rate of air circulated to the upstream side increases, and therefore the circulated air flows back to the air flow meter. As a result, the precision with which the air flow meter detects an intake air flow rate deteriorates. The supercharging internal combustion engine according to the prior art suppresses deterioration of the intake air flow rate detection precision by limiting a detection signal from the air flow meter to a predetermined range during vehicle deceleration.